This invention is directed to a computer system for dynamically modeling information systems of organizations.
Early computer information processing systems stored, retrieved, and modified data contained in files specifically created for each information processing application. Knowledge relating to the structure and content of each data file was coded directly into each application program. When a need later developed to use the data within the data file for additional purposes, the user often created other primarily redundant data files, writing a specific application program to interact with each of these files. Subsequent changes in the content of any data file frequently mandated modification of related data files. If the user wished to avoid creating redundant data files, those modifications necessitated by additional demands were made to the original data file. Again, application programs were written to perform new tasks on the modified file.
However, the data file modifications sometimes hampered operation of earlier application programs, thus requiring their modification. As a consequence, computer installations involved in data processing faced the recurrent task of choosing between data file redundancy and repeated software modifications.
With the advent of so-called data base management systems, many of the problems encountered in the early information processing systems were alleviated. In addition to removing the need for the application program to address the intricacies of data file manipulation, data base management systems promoted efficient design, enhanced file maintenance and modification, eliminated data file redundancy, and provided substantial documentation regarding data file structure.
With the shift to data base management systems, the concept of dual data representation fully emerged. The first level of data representation, the physical representation, relates to the manner in which individual data records are stored and how their inter-relationships are depicted. The second level of data representation, the logical representation, describes the data base users' view of the data. The physical representation of the data is generally of no concern to the data base user. Rather, the task of manipulating individual data storage areas is left to the data base management system. Of concern to the data base user, however, is the logical representation of the data, since the users' ability to store, retrieve, and modify aggregations of data items, data records, and data relationships is dependent upon the form in which the data base management system presents data to the user.
Information management systems handle complex environments often consisting of hundreds of elements and relationships, permitting users to manipulate and employ data in ways not always anticipated by systems designers. Representation of such elements and relationships to a user presents a unique set of problems not encountered, and certainly not resolved by present data base management systems. Instead of being organized into application-oriented files, which are always addressed in the same way, as in data base systems, the information is organized so that it can be addressed in a variety of different ways, and can be used to answer a diversity of queries. All the interesting facts about entities are stored together rather than merely those facts needed for one application. As pointed out by J. Martin, "Computer Data-Base Organization", 2d ed., chapter 3, pp. 24-25 (1977), this "reservoir" concept of information systems is much easier to conceive than to implement. It is a complex and lengthy operation to build up such data bases, and it is expensive to search sufficiently quickly to give real-time answers to unanticipated queries.
The management of information has evolved into the field of Computer Aided Systems Engineering (CASE). As described by C. Gane, "Computer-Aided Software Engineering: The Methodologies, the Products, the Future" (1988), some of the common characteristics among CASE products are that they internally build a design database "at a higher level than code statements or physical data element definitions," and that they "typically hold[s] information about the data to be stored in the system, the business logic of the processes to be implemented, their physical layout of screens and reports, and other requirements/design information."
There are several such CASE products presently available. Two such products are EXCELERATOR, from Index Technology, Cambridge, Mass., and IEW, from Knowledgeware, Inc., Atlanta, Ga. EXCELERATOR enables an operator to work with data flow diagrams and data model diagrams, structure diagrams. An operator may also modify, delete, copy, rename, list or add a diagram. Diagram objects may be user defined, and are stored in a dictionary.
In a similar manner, IEW enables a user to work with, and create or change objects on diagrams, which affects an encyclopedia but not existing displays or screens. In addition, IEW can model relationships, entities and attributes together, or entities alone, but does not model attributes alone. It is often useful to manipulate attributes independent of entities to which they may later be tied.
Accordingly, it is an object of the present invention to provide an improved information management system.
Other objects, features and advantages of te invention will be apparent from the following description of the preferred embodiments thereof, and from the claims.